Packaging method



Dec. 24, 1940. H. F. WATERS PACKAGING METHOD INVENTOR. 545/ E 1444755;

ATTORNEY.

Filed May 15, 1937 Patented Dec. 24, 1940 UNITED STATES PATENT OFFICE 6Claims.

This invention relates to improvements in the packagingv of commoditieswhich deteriorate rapidly when exposed to the atmosphere, and moreparticularly to an improved method for the packaging of such materialsin bags, preferably utilizing vacuum packagr' .ig principles.

In the packaging of those commodities which deteriorate when exposed tothe atmosphere for any length of time it is essential that the packagebe air-tight and/or gas-tight. The formation of a suitable packagebecomes even more important if the commodity to be packaged is coffee.In the following description my improved method of packaging materialswill be explained with reference to the packaging of coifee, although itis to be understood that it is applicable to the packaging of thosematerials which generate or which are capable of generating gas.Sauerkraut may be cited as another example.

Coffee has very definite characteristics not possessed by other foodcommodities. Coffee in the bean form must be roasted, and before it isused it must be ground to that fineness required by the particularmethod used in preparing the beverage.

The coffee bean is essentially fibrous in character, containing aplurality of cells, and when roasted, carbon dioxide gas is formed inthe cells. Moreover, during the roasting operations there are developedaromatic and vegetable or fixed oils. The aromatic oils are volatilesothat they will pass very quickly into the atmosphere unless some meansare provided to prevent such evaporation. The vegetable and fixed oilsreadily become rancid when exposed to the oxygen of the atmosphere, andindeed, coffee in bean form after being roasted will not retain much ofits desirable properties if exposed to the atmosphere much longer thanthirty days. Ground coffee will lose the greater part of its desirablecharacteristics in a much shorter time; in a majority of cases in abouta week or ten days. When the carbon dioxide is lost, the rapiddeterioration of the coiiee becomes inevitable.

In order to reduce the loss of these essential oils and the carbondioxide, it has been proposed to package ground coffee under vacuum,using rigid containers for the purpose. However, since a space isusually left between the cover of the container or can and the top ofthe coffee, the carbon dioxide generated by the coffee will soon passinto this space. The coffee is loosely, confined in the container andmakes it possible for each particle to give off the gas very readily.

The vacuum created also accelerates the rate at which the carbon dioxideis evolved so that instead of the coffee being in fact packaged undervacuum, it is only sotpackaged for a very short time. When the cover isremoved from a can containing cofl'ee originally packaged under vacuum,'the carbon dioxide will quickly become dissipated in the air., Once thecover has been removed it is impossible as a practical matter to retainthe volatile, aromatic oils in the coffee so that it soon becomes staleand rancid.

In accordance with the present invention I propose to package coffee,utilizing vacuum principles of packaging but employing a fiexiblecontainer made of some suitable material, as for example that productsold under the trade-named Pliofilm, or paper coated with some'suitablematerial which will render the paper air-tight. Preferably I employ athermoplastic coating possessing the above characteristics such as, forexample, a rubber hydrochloride coating, since in closing the package itis highly essential that no small openings occur in the closure;otherwise the advantage of my packaging method will be lost. Otherthermoplastic coatings possessing the same necessary characteristics maybe used if desired. 7

Accordingly, one of the many objects of my present invention is toprovide a method for the packaging of materials which generate a gassuch as, for example, coffee, sauerkraut and the like, wherein thematerial is first placed in a bag made of flexible gas-tight materialand the walls of the bag are then collapsed against the material toconfine the latter in a compact, comparatively rigid mass. Since thematerial is in effect packaged under pressure, the rate at which thegaswill be evolved will be lower than the rate at which the gas would beevolved if the material were packaged in a vacuum or according to theusual methods of packaging materials.

Another object of my present invention is to provide an improved methodof packaging commodities of the type above described, particularlycoifee, in which the cofiee is placed in an airtight and/or gas-tightcontainer or bag made of flexible material of the type above described,subjected to a vacuum, and thereafter sealed. By this method the wallsof the bag are collapsed, due to atmospheric pressure, against thecoffee, and the coffee is retained in a compact condition. I have foundthat by utilizing atmospheric pressure to exert a force on the packagedoofiee, the amount of carbon dioxide gas liberated by the coifee will bereduced to a minimum so that the aromatic and volatile oils will notbecome dissipated over a considerable length of time. This isparticularly important when the package is opened since, due to theslowness of the liberotion of the carbon dioxide, the amount of aromaticoils lost when the package is opened will 5 be practically negligible.In order to prevent the breaking ofthe container due to the pressuregradually built up by the liberation of the carbon dioxide gas, I alsocontemplate the provision of an excess of material in the bag which willpermit the formation of a space above the coffee into which the carbondioxide may fiow as it is being liberated. It is to be understood inthis connection that this space is not analogous to the space nowprovided in coffee packages of the rigid type since, when the package isformed, the wall portions of. the bag forming the top thereof arepressed against the coffee due to the vacuum packaging operation. Theexcess of material permitting the formation of such a space is createdby sealing the bag some distance from the top of the coffee. This spaceis only brought into existence upon the formation of the carbon dioxidegas.

Another object of my present invention is to provide in a method andpackage of the type above described, a suitably constructed outercontainer to which the bag or flexible container mayv be secured byspaced lines of adhesive. Preferably these lines of adhesive are soarranged as to- 30 assist in holding the bag opening as it is beingfilled with coffee and during the time when the vacuum is being appliedthereto so that complicated handling machinery will not be needed.

These and other objects of my present invention will become moreapparent from a study of the following description taken in connectionwith the accompanying drawing, in which like numerals indicate likeparts, and in which:

Fig. 1 is a view, in perspective, of a bag filled 40 with coffee andpackaged under a vacuum in accordance with my present invention, certainparts being broken away to show the contents;

Fig. 2 is a view, in perspective, of the completed package, the innerbag being shown in 45 dotted outline;

Fig. 3 is a view, in perspective, of a modified form of package showingthe method of forming the closure thereof, the inner bag and adhesivelines being shown in dotted outline;

50 Fig. 4 is a vertical sectional view through the modified form ofpackage illustrated in Fig. 3.

Referring now to the drawing and more particularly to the modificationsdisclosed in Figs. 1 and 2, there is shown a bag l provided with 55gussets II. The bag is filled with roasted coffee l2 either ground or inthe bean and the walls of the bag are collapsed against the coffee. Froman inspection of Fig. 1 it will be noted that the bag walls are alsocollapsed against the top of 60 the coffee so that the latter isconfined under pressure in a compact mass. Preferably the walls of thebag are collapsed by evacuating the container. In this way theatmospheric pressure is utilized to force the bag walls against thecofiee.

65 While the vacuum is still being applied the bag is sealed along sealline [3. In order that the bag may be suitably secured to a vacuumpackaging apparatus, I have provided an extension of the bag I4extending above the seal-line I3.- Al- 70 though any form of vacuumpackaging mechanism may be employed, I prefer to use the type ofapparatus disclosed and claimed in my copending application Serial No.180,591, filed December 18, 1937, which is a continuation of my 75application Serial No. 20,371, filed May 8, 1935,

for Machine and method for packing commodities." Similarly, although thebag may be made of any material which will prevent the seepage of airthrough the bag seams and through the material itself, I prefer eitherto use a bag made of rubber hydrochloride such as that material soldunder the trade name Pliofilm" or a bag made of paper coated withair-tight and thermoplastic adhesive.

Similarly, although the bag may be constructed in accordance withstandard bag making methods, it is essential that the seams of the bagbe so formed as to prevent any possible leakage. As will be appreciated,small pinholes will destroy the utility of the package.

When vacuum is applied to remove air from the bag, the latter, beingmade of flexible material, will be collapsed to the differential inpressures in the inside and outside of the bag. Moreover, that portionof the bag between the top of the contents and the seal-line l3 will bein part collapsed against the contents and against each other as isclearly illustrated in broken outline in Fig. 1 designated generally bythe numeral IS. The contents will, therefore, be retained in anextremely compact condition with the result that the carbon dioxide willbe liberated very slowly and its protective character will consequentlybe retained. Breakage of the container, due to the slow liberation ofthe carbon dioxide, will be prevented since it will be collected betweenthe top of the contents and the seal-line I3. In fact, tests of mypackage have shown that the rapidity with which the carbon dioxide givenoil by the coiIee is decreased to one-fifth of the rate at which it isgiven off by the so-called vacuum tin type of packages. The outercontainer I5 is provided with conventional closure flaps I! which aresealed to each other in any conventional manner.

After the coffee has been packaged in the manner just described, the bagmay be placed in an outer countainer or carton l5 made of relativelyrigid material which may carry the usual form of advertising matter anddress. Since the extension of the bag I4 is no longer needed, it may becut off just above the seal-line l3 and the remainder folded overagainst the body of the bag.

Referring now to the modification illustrated in Figs. 3 and 4, I haveshown a bag I0 provided with gussets II and containing coffee l2.Instead of filling the bag and applying vacuum before it is placed in anouter container, I have found that in some cases it is desirable tosecure the bag in the outer container before the filling, vacuum andsealing operations. Accordingly, either the bag or the outer container,in the embodiment shown, the bag, is provided along two opposite wallsand adjacent .the bottom thereof with adhesive lines l8. Similar linesof adhesive l9 are located at the bottom of the outer container. Whenthe bag is inserted in the outer container these adhesive lines cause anadherence of the bag to the outer container. In order to hold the bagmouth open, lines of adhesive 20 are provided along the inner surface ofthe two opposite side flaps 2| so that when these flaps areopened thebagmouth will also be opened, due to the adhesion of the walls of the bagto these adhesive lines 20. After the bag has been filled into operativeposition. This extension I4 is then folded back upon itself andthereafter the end flaps 22 are folded into position in the conventionalmanner. When the wall portions forming the bag mouth are broughttogether there will be provided an excess of material 23 which normallywould extend beyond the area of the container proper and against theflaps 22.

However, this portion will not prevent the closing of the closure flapsof the outer container, since it may readily be folded upon itself andagainst one of the flaps 2|. When the package is opened a portion of theexcess material 23, including a section of the seal, may be cut so thatwhen the extension I4 is opened up a pouring spout may be provided.

It will be appreciated by those skilled in the art to which thisinvention pertains that many alterations and changes may be made inconstructional details and forms of package without departing fromeither the spirit or scope of the invention. It is therefore to beunderstood that the invention is to be limited only by the appendedclaims which are to be broadly construed.

I claim:

1. In a method for the packaging of roasted coffee, the steps of fillinga gas-tight flexible bag with the coffee, removing air from said bagwhile the outer surfaces of the bag are subjected to atmosphericpressure to collapse it against the coffee to hold the latter confinedin a compact mass, sealing the collapsed mouth of the bag at a distanceabove the top of the coffee whereby as gas is evolved from the coffeethe pressure of the gas will be dissipated through the expansion of thebag between the top of the coffee and the sealed section of the bag.

2. In a method for. the packaging of roasted coffee, the steps offilling a gas-tight flexible bag with coffee, removing air from said bagwhile the outer surfaces of the bag are subjected to atmosphericpressure to collapse the walls of the bag under atmospheric pressureagainst the coffee in all directions and to collapse the walls of thebag above the coffee against each other, sealing the mouth of the bagabove the top of the cofiee to leave a section of the bag between theseal and the coffee, whereby to provide an area which may be opened bythe gas evolved by the coffee without destroying the seal or breakingthe bag.

3. A method of sealing bags whereby space is provided for internalexpansion after final sealing which consists in collapsing the bag mouthand applying heat thereto in a zone located above the initial contact ofthe mouth walls a distance sufficient to accommodate fluid expansionwithin the bag, said steps being carried out while the bag is exposed toatmospheric pressure.

4. A method of providing space for atmospheric expansion within theinterior of an hermetically sealed bag which consists of flattening thewalls of said open mouth of bag after same has been fllled withcontents, thus causing a lessening of atmospheric volume within theinterior of said bag, and when in flattened position sealing the upperportion only of said flattened walls, said steps being carried out whilethe bag is exposed to atmospheric pressure.

5. A method of sealing the open mouth of a material containing bagconsisting of bringing together in flattened relationship the twoopposite walls of said mouth, and thereafter uniting the interiorsurfaces of said two opposite walls by means of heat over apredetermined limited portion of said flattened area spaced away fromthe initial line of contact of the walls so as to provide a substantialexpansion zone in the bag above the material therein, said steps beingcarried out while the bag is exposed to atmospheric pressure.

6. A method of closing the mouth of a bag made of substantiallyimpervious material having contents therein, which consists of bringingtogether in flattened position two opposite walls of said mouth andwhile in flattened position effecting an air tight seal above the baseof the flattened portion, sufficiently to permit the subsequentexpansion within the sealed bag, said steps being carried out while thebag is exposed to atmospheric pressure.

HARRY F. WATERS.

